RNA interference mediating small RNA molecules

摘要

Double-stranded RNA (dsRNA) induces sequence-specific post-transcriptional gene silencing in many organisms by a process known as RNA interference (RNAi). Using a Drosophila in vitro system, we demonstrate that 19-23 nt short RNA fragments are the sequence-specific mediators of RNAi. The short interfering RNAs (siRNAs) are generated by an RNase III-like processing reaction from long dsRNA. Chemically synthesized siRNA duplexes with overhanging 3′ ends mediate efficient target RNA cleavage in the lysate, and the cleavage site is located near the center of the region spanned by the guiding siRNA. Furthermore, we provide evidence that the direction of dsRNA processing determines whether sense or antisense target RNA can be cleaved by the produced siRNP complex.

主权项

1. An isolated double-stranded RNA molecule, comprising:
(i) a sense strand and an antisense strand that form a double-stranded region consisting of 14-24 base pairs; (ii) at least one strand having a single-stranded 3′-overhang; and (iii) at least one nucleotide analogue,wherein said RNA molecule is non-enzymatically processed and is capable of target-specific RNA interference, and said sense strand has an identity in the double-stranded region of at least 85 percent to a target RNA molecule.